Recently, organic electronics devices have drawn increasing attention. The devices are characterized by flexibility, applicability to a large area, and feacibility of employing a low-cost and high-speed printing process in manufacturing electronics devices. Typical devices include an organic EL element, an organic solar cell element, an organic photoelectric conversion element and an organic transistor element. An organic EL element is expected to be a main target for a flat panel display in the next-generation display and has been applied to displays of mobile phones through TV sets and the like. The development of organic EL elements has been continued toward further higher functionalization. Organic solar cell elements and the like have been researched and developed for a flexible and inexpensive energy source. Organic transistor elements and the like have been researched and developed to be applied to flexible displays and low-cost ICs.
To develop these organic electronics devices, it is very important to develop semiconductor materials constituting the devices. Acene organic semiconductors such as pentacene, which is a low molecular weight semiconductor material, have been aggressively investigated for an organic transistor material. Regarding heterocyclic compounds, hetero acene compounds, in particular, containing a sulfur or selenium atom, have been mainly investigated, and benzodithiophene (DPh-BDT), naphthodithiophene (NDT), benzothienobenzothiophene (DPh-BTBT, AlkylBTBT) and dinaphthodithiophene (DNTT) have been developed for materials stable in the air and having high performance (Patent Literatures 1-5, Non Patent Literatures 1-5). These compounds have more excellent semiconductor properties and higher stability as compared to pentacene, but the performance of these compounds appears to be still insufficient. In fact, these compounds have not been commercially exploited. In the circumstance, it is still important to develop a semiconductor material having a high carrier mobility and high stability (i.e., high heat resistance and high weather resistance) and useful for various devices.